Method of production of calcium-bisulfite liqour.



H. 0. v. BERGSTRUM.

- METHOD OF PRODUCTION OF CALCIUM BISULFITE LIQUOR.

' APPLICATION FILED SEPT-25,1914.

1 1 559,352, Patented Nov. 9, 1915.

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HILDING OLOF VIDAR BERGSTROM, OF STOCKHOLIVI, SWEDEN.

METHOD PRODUCTION OF CALCIUM-BISULFITE LIQUOR.

Specification of Letters Patent.

, Patented Nov. 9, 11915.

Application filed September 25, 1914. Serial No. 883,492. g

Tooll whom it may concern.

Be it known that I, HILDING OLoF VIDAR Bnncs'rnom, civil engineer, subject of the King of Sweden, residing at Kung sklippan 17 Stockholm, in the Klngdom of Sweden, have invented certain new and useful Improvements in Methods of Production of Calcium-Bisulfite Liquor.

The vapors from a sulfite boiler contain, as is well known, sulfur. dioxid, which at present is usually turned to account by passing these vapors, or their product of condensation, into the so called acid bins containing ready-made calcium bisulfite, (the acid liquor used in the boiling process) whenthe latter is enriched with the amount of sulfur dioxid contained in the vapors. As however these vapors contain conslderable'quantities of impurities, 'the calcium bisuch as oil, alcohol etc., removingthe impuritles occurring 1n the vapors to a greater.

or lesser extent. The calcium bisulfite, produced according to the present invention, is therefore purer than has hitherto been the case.

The method of procedure is mainly based upon the fact that the vapors are condensed, and then by one or more operations the sul- .furdioxid is' separated from the impure product of condensation, which is drawn ofi', and the sulfur dioxid turned into use in the process, .6. g. by passing the same into the acid tower Where the calcium bisulfite is being produced, or into the ready made cal-' cium bisulfite, and so on.

The manner of carrying out this method becomes apparent vfrom the description below ofthe system of apparatus diagrammatically shown on the accompanying drawing.

Figure 1 is a diagrammatic view of the apparatus suitable for carrying out the method, and Fig. 2 is a partial matic view of a modification.

I The vapors issuing from. the boiler A (Fig. 1) are condensed in the usual manpipe 9 in the tank G can then be treated for extrac'ting one or more of the'organic proddiagrambe again turned to use in the process, 6. g.

by being run into the acid towers (not shown) or into the acid bins and so on. From the cooler B there issues furthermore into the tank D through the pipe Z2 the product of condensation formed in the cooler B, and this'product of condensation generally contains sulfur dioxid. This product of condensation is run from the tank D, through the pipe (P, to an apparatus for expelling the sulfur dioxid and other volatile substances, which device might properly be a column apparatus E, in which it is allowed in the usual manner to run down in the opposite direction to the steam which is coming from below. The steam expels then the sulfur dioxid together with some organic substances, such as oil, etc. This vaporous mixture may now either be run direct into the process, or as is shown in the drawing, through the pipe 6 transmitted to the cooler F. The product of condensation which has been purified of sulfur dioxid and other substances, and which contains some impurities, is drawn ofl' from the column-apparatus through the pipe 6 The product of condensation, formed in the cooler F as well as vaporous sulfur dioxid pass off through the pipe f, from which the sulfur dioxid continues through the pipe f, in order to be turned to account in the process, 6. g. in the acid towers or acid bins, while the liquid product of condensation generally containing S0 passes down into a tank G. This latter is adapted for heating 6. g. by means of a spiral tube K, through which the steam passes, and as the result of this heating, the

sulfur dioxid is expelled, and may through.

the tank G, a return-flow cooler L, or some similar device may be connected wit-- the The product of; condensation left ucts contained in the same. It is advisable to combine with the tank G an oil separator, so that the greater part of the oil is removed when the product of condensation comes into the tank G.

The sulfur dioxid coming from the pipe 7 can usually not be run direct either into the acid towers or into the acid bins, as then a varying counter pressure may easily occur in the column-apparatus. On account of this it is advisable to run the same into a separate absorption device, 6. g. into a tower M filled with cokc,where the S0 is absorbed. This solution is made use of then in the process of manufacture, e. g. by being run into the acid bin.

In such cases where the mixture at the end of a boiling process is being expelled from the boiler with the aid of the pressure in the same, the present principle may also be made use" of. In this connection the method of procedure may for example be such as will be seen from Fig. 2, according to which the pulp mass and the liquor from the boiler A are turned into the tank S, from which the vapors issue through the pipe S into a cooler 13, after which the process is the same as according to Fig. 1.

It is evident that the system of apparatus shown and the description of the method of procedure with the same are only illustrative, and merely intended to explain the courseof the process in the main. In practical use there are therefore to be added some items and detail devices not given here, as'they have nothing to do with the characteristics of the invention. The product of condensation may for example, before being taken into the expulsion device, by heating the same or by the addition of SO neutralizing matter, etc., be more or less completely ridded of S0 Even a concentrated prodnot of the organic substances, 6. g. oil and methylated spirit, may be taken out from c. g. a special department or chamber arranged for that purpose in the column, or

in some other manner, when mainly SO passes off from the expulsion device as gas. Vapors from the expulsion device may even be run through S0 neutralizing substances,

when in a succeeding condensation a product'of condensation more or less free from S0 is obtained. In a manner known for the column apparatus the organic substances may furthermore be obtained directly in ahalf or entirely pure condition from the expulsion device.

Having thus described my invention, I declare, that what I claim is:

1. The herein described method for producing calcium bisulfite in the manufacture of sulfite cellulose under utilization of the vapors from the sulfite boiler or the acid. liquor, which consists in condensing the lecting the gaseous sulfur dioxid not con densedin said condenser and reusing it in the sulfite process, introducing "the condensate obtained in said condenser in an app-aratus in which .sulfur dioxid together with some organic substances are driven off, and then introduced in a second condenser, leading off the sulfur dioxid from said condenser and reusing it into the sulfite proc-' ess, while the condensate is led off from said condenser and collected.

3. The herein described method for producing calcium bisulfite in the manufacture of sulfite cellulose under utilization of the vaporsfrom the sulfite boiler or, the acid liquor, which consists in condensing the vapors from the sulfite boilers or the said liquor in a condensing apparatus collecting the gaseous sulfur dioxid not condensed in said condenser and reusing it in the sulfite process, introducing the condensate obtained in said condenser in an apparatus in which sulfur dioxid-together with some organic substances are driven off and then introduced in a second condenser, leading off the sulfur dioxid from said cond enser and reusing it in the sulfite process while the condensate is led off from the condenser and collected in a receptacle where by means of heat the sulfur dioxid contained therein, is driven off and reusedin the sulfite process.

4. The herein described method for producing calcium bisulfite in the manufacture of sulfite cellulose under utilization' of the vapors, from the sulfite boiler or the acid liquor, which consists in condensing the vapors from the sulfite boilers or the said acid liquor in a condensing apparatus collecting the gaseous sulfur. dioxid not condensed insaid condenser and reusing it in the sulfite process, introducing the condensate obtained in said condenser in an apparatus in which sulfur dioxid, together with some organic substances are driven off and then introduced in a second condenser, leading off the sulfur dioxid from said condenser and reusing it in the sulfite process While the condensate is led off from saidcondenser and collected in a receptacle where by means 0 heat the sulfur dioxid contained therein, is driven off leading the gases issuing from said receptacle through a return flow cooler and reusingthe gases not condensed in said cooler in the sulfite process.

5. The herein described method for producing calcium bisulfite in the manufacture of sulfite cellulose, under utilization of the vapors from the sulfite boiler or the acid liquor which consists in condensing the vapors from the sulfite boilers or the said acid liquor in a condensing apparatus collecting the gaseous sulfur dioXid not condensed in said condenser and reusing it in the sulfite process, introducing the condensate obtained in said condenser in an apparatus in Which sulfur dioXid together With some organic substances are driven off, introducing the gases from said apparatus into an absorption apparatus in which sulfur dioXid is absorbed,

and then reused in the sulfite process, the

gases not absorbed in said absorption apparatus being condensed and collected.

6. The herein described method for producing calcium bisulfite in the manufacture of sulfite cellulose under utilization of the vapors from the sulfite boiler or the acid liquor, which consists in condensing the vapors from the sulfite boilers or the said acid liquor in a condensing apparatus collecting the gaseous sulfur dioXid not condensed in said condenser and'reusing it in the sulfite process, introducing the condensate obtained in said condenser in an apparatus in Which sulfur dioXid together With some organic substances are driven off, and then introduced in a second condenser, leading off the sulfur dioxid from said condenser and reusing it in the sulfite process While the condensate is led off from said condenser and collected in avreceptacle Where by means of heat the sulfur dioXid contained therein, is driven off, introducing the gases from said apparatus into an absorption apparatus in which sulfur reused in the sulfite process.

dioxid is absorbed, and then 7. The herein described method for producing calcium bisulfite in the manufacture ,of sulfite cellulose, under utilization of the vapors fromthe sulfite boiler or the acid liquor, which consists in driving off the mass and the liquor from the boiler by the influence of the pressure in the boiler into a closed receptacle leading the gas from said receptacle into a condenser collecting the gaseous sulfur dioxid not condensed in said condenser and reusing it in the sulfite process, introducing the condensate obtained in said condenser in an apparatus in Which sulfur dioxid together With some organic substances are driven off and then introduced into a second condenser, the sulfur dioXid not condensed in said condenser being reused in the sulfite process, and collecting the condensate. k

8. The herein described method for producing calcium bisulfite in the manufacture of sulfite cellulose under utilization of the vapors from the sulfite boiler or the acid liquor, which consists in condensing the vapors from the sulfite boilers or the said acid liquor, treating the condensate thereby obtained in such a Way, that sulfur dioxid contained therein is separated from the condensate, reusing said sulfur dioxid' in the sulfite process and introducin the remaining condensate into an apparatus in which organic substances are driven off and collected.

In Witness whereof I have hereunto set my hand in presence of two Witnesses.

HlLDING OLOF VIDAR BEResTRoM.

Witnesses AUG. HAGELI ALMA PETEERSSON. 

